Conventional practice in the design and manufacture of electrodes for batteries, especially rechargeable lithium batteries, involves the fabrication of powder-based electrodes in which the electrochemically active material is an ion-storage compound, but in which there is also a substantial amount of conductive additive, typically a high surface-area carbon, as well as an organic (polymeric) binder. In addition there is open porosity into which liquid electrolyte is infused to facilitate ion transport throughout the electrode.
Typical carbon additives and binders have low materials densities, e.g., <2.2 g/cm3 and <1.5 g/cm3, respectively, and take up a substantial volume fraction of the electrode. Thus, use of conductive additive and/or binder lowers the volume and mass fraction of the storage material in the electrode and degrades the energy density of the resulting cell.
Furthermore, electrodes are typically fabricated by suspending and/or dissolving said constituents including the active material powder, conductive additive, and binder in a solvent, coating the resulting suspension onto a metallic current collector, drying said coating, and pressing or calendaring said electrode before it is used to construct a cell of either the wound or stacked type. The manufacturing throughput for electrodes is limited by the time required for each of these steps, and especially the drying step during which solvent is removed.